When a business model allows selling a product at little or no cost and recoups the product's cost by selling services, such as with cellular phones, a key element is the ability to render the product useless if the terms of the service contract are not fulfilled. For example, if a cellular phone service subscriber fails to pay the agreed-to monthly fee, the service provider can simply turn off the phone's access to the network. Because the value of the phone is extremely limited if it cannot make phone calls, the service provider's investment is protected. Further, because the cellular phone may have little or no street value, there is little incentive to defraud the service provider for the sole purpose of getting an inexpensive cellular phone.
However, a subsidized computer may have considerable use and value when not connected to a network. Therefore, a business model that supplies computers or other high intrinsic value electronic devices to consumers at a subsidized initial cost along with a services contract, e.g. Internet service access, must have a way of limiting access to the computer when the terms of contract are not fulfilled. Given the sophistication and ingenuity of hackers, it may be difficult, if not impossible, to provide cost effective protection from every possible hack. One significant danger is a software-only hack that can be virally spread through the Internet and executed using a script.